How much does it cost to fix Sime error code AL 06?

Typical repair cost for the Sime AL 06 fault is £120-250 including labour.

AL 06 High

Sime AL 06 Fault Code

Q: What does the Sime AL 06 fault code mean?

Your boiler has stopped working because it failed to light the flame properly, likely due to an issue with the gas supply, the ignition process, or the exhaust system.

Also written as AL06 — same fault.

The Sime AL 06 fault code means: your boiler has stopped working because it failed to light the flame properly, likely due to an issue with the gas supply, the ignition process, or the exhaust system.. It appears on 22 Sime models in our database.

Technical description: LOCKOUT

Typical repair cost £120-250 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Sime models that show the AL 06 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Sime AL 06 fault code information on this page is sourced and cross-checked against the official Sime service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026